Lleyton Hewitt accused Bernard Tomic of blackmail and physical threats against him and his family in explosive allegations on Thursday as Australian tennis plunged to new lows.
The veteran two-time grand slam champion said Tomic would never again feature in Davis Cup while he captained the Australian team. He called Tomic a "clown" and said he did not want anything to do with him.
"We're trying to set cultural standards for the Davis Cup and representing Australia. He hasn't really been close to those for in the last couple of years," Hewitt told reporters.
He was responding to Tomic's claims this week that Hewitt had ruined the national system and "no one likes him any more".
The former world No 1 said Tomic had attempted to blackmail him by demanding a wildcard and threatening to refuse to play Davis Cup, saying their once-close relationship was over.
"I think the threats that I have received for me and my family, that I've had for a year-and-a-half now, I don't think anyone would reach out to a person that speaks like that," he said.
Asked what sort of threats, he replied: "They were blackmail threats and physical.
"For me the biggest frustration is that I feel like I really went out of my way to help Bernie, especially when I first came into the role [as Davis Cup captain].
"At the end of the day he still kept making the same mistakes, For me, it was probably the abuse that I copped from him that in the end I drew a line in the sand, and I haven't spoken to him since.
"It will [continue]. He won't play Davis Cup while I have anything to do with it."
The combustible 26-year-old unloaded on Hewitt after being bundled out of the Australian Open at the first hurdle to sixth seed Marin Cilic.
Tomic, who has long had a fractious relationship with Hewitt and Tennis Australia, claimed that he and countrymen Thanasi Kokkinakis and Nick Kyrgios "don't want to play [Davis Cup] any more because he's ruined the system".
"Go away," he said of Hewitt. "Like, literally. If you've retired, why are you still in tennis?"
Tomic, who rose to a career-high No 17 at his peak, has not played Davis Cup since 2016 and alleged Hewitt "doesn't put the players first".
Tomic is no stranger to controversy after a series of run-ins with the authorities down the years.
At Wimbledon in 2017, he was fined for claiming he was bored by tennis and had faked an injury. His racket sponsor dropped him as a result.
Last year he even appeared on Australian reality TV show "I'm a Celebrity... Get Me Out of Here".